I didn't understand exactly what you were wanting in a short shift. I was thinking on the lines of what the 4500 has where the shift tower is toward the rear of the cover. The shift dynamic is different on those.
However, I was watching a driver trying to shift a fairly new Dodge and he was certainly having more difficulty than I ever do with the Getrag. What I would like for myself would be a cover assembly that had the tower on the rear which would move the shifter closer to where I sit (tall and long legged) thus giving me a short shift simply by reducing the length of the shift lever.
Now if someone made those- - - -
James